How Much Is That Doggie (Worth) In The Courthouse?

The one with the wiggly nose

Can a dog testify in court?

Can a dog’s testimony be enough to result in a conviction on a murder charge?

These are not hypothetical questions.

It all starts with an important difference between dogs and humans – the differential ability of these two species to use their nose. Quite simply, dogs are almost infinitely better at sniffing things out than are humans. Dogs have about 50 times the number of scent receptors than do humans. The noses of many dog breeds are shaped to draw more air through the nose. Dogs have a separate passage-way in their noses that brings exhaled air past their scent receptors. Dogs even have an organ that humans do not possess. Located at the top of a dog’s mouth, the vomeronasal (Jacobson’s) organ allows dogs to detect different pheromones. It all adds up to dogs having a sense of smell that is 10,000 to 100,000 times more acute than that of humans.

Dogs are man’s best friend, so naturally humans have exploited this canine ability to smell. Dogs have been used to track escaped convicts and lost children, find explosives and drugs, and diagnose diseases such as cancer and diabetes.

During the Vietnam War, the American military discovered that dogs could be trained to be remarkably good at finding human remains. The smell of decomposing human flesh gives off a unique odor that is remarkably “sticky” on anything touched by a dead human. The scent of a dead human differs from other animals and can linger for years or decades. Just as a dog can be trained to sniff out drugs or explosives, a dog can be trained to find a dead human being. There is a small subset of the dog-training community that raises and trains “cadaver dogs.” Their most common use is locating non-survivors of natural disasters such as hurricanes and earthquakes. A few days after these disasters, the work of the people-finding dogs ends and the work of the corpse-finding dogs begins.

A random and irrelevant thought: While we are living, our physiological makeup and much of human psychological processes appear to be most closely related to rats. That’s why rats are so commonly used in both medical and psychological experiments. While we decompose, the scent we give off most closely resembles that of pigs. As a result, pig flesh is often used while training cadaver dogs. It is a little disconcerting to realize that humans most closely resemble rats in life and pigs in death.

Cadaver dogs have also been prominent in “no-body” homicide cases – that is, homicides were the killer hid or destroyed the body of their victim. The uncontroversial use of cadaver dogs is in corpse-location. A cadaver dog can often sniff out where the body was buried, thereby turning a no-body investigation into a more traditional homicide investigation. The dog’s ability is proven by digging up the corpse.

The evidence from cadaver dogs is more controversial when they find a scent, but no body. For example, a cadaver dog might indicate that a body was once in the car trunk of a suspect. Along with the scent, a dirty shovel might suggest that the body of the missing person was transported to an unknown burial location. In Florida, shovels are often absent, but proximity to alligator-infested swamps raises different hypothesis about the location of the missing putative homicide victim.

In these cases, prosecutors want to use the findings of the cadaver dog as evidence in court. This presents problems and controversies.

First, the dog is indicating that a human corpse was once present. It cannot determine whose body was present or when it was there. The evidence of the cadaver dog must be embedded into the other, often circumstantial, evidence of the case.

Second, cadaver dogs are not infallible. A dog must achieve a tested accuracy rate of at least 95 percent in order to be certified as a cadaver dog. This is a remarkable accomplishment, but does the remaining 5 percent cross the line for reasonable doubt in a criminal trial?

These are important considerations for a judge to weigh when deciding whether to rule cadaver dog evidence as admissible in a no-body homicide prosecution, but there is something even more profound.

In the context of a criminal trial, the cadaver dog is serves as a witness against the accused. A fundamental principle of Canadian and American criminal law is that the accused (or their lawyer) can cross-examine witnesses. Despite millennium of living together, a linguistic divide still separates dogs and humans. A dog cannot be cross examined. Instead, the dog’s handler takes the stand to say, “the dog sat on this spot. It does this when it has detected the smell of human flesh.” It is a form of hear-say (act-say?) evidence – and hear-say evidence is generally not admissible as evidence.

So how do judges resolve this question in courts? Is the behavior of cadaver dogs admissible as evidence in a no-body homicide prosecution? Will a jury be told that the dog sniffed out the residual odor of a body in the trunk of the suspect’s car or in his basement?

Judges have ruled both ways on the admissibility of this type of cadaver dog evidence. The general rule seems to be that if the prosecution’s case is a strong one - if there is a lot of evidence that the suspect is guilty - the cadaver dog’s silent testimony will be ruled admissible; it will be just one more piece of evidence in an already strong case. If, on the other hand, the case is otherwise weak, most judges will rule the cadaver dog evidence inadmissible. Most judges will not give a jury the opportunity to talk themselves into convicting primarily on how a dog behaves.

One last point.

Sometimes a dog can cause a conviction even when the dog’s evidence was flawed. Let’s take a quick look at one such conviction in a no-body case. On this occasion, it was a tracking dog but the general principle remains valid.

In 1980, a young college student in Virginia named Gina Hall went to a nightclub to dance one Friday evening. She met a guy named Stephen Epperly. They hit it off. A group of Epperly’s friends were going to a lake-side cabin for a midnight swim. Gina was invited along. She agreed. She and Epperly left the nightclub in her car. She was never seen again. It appears that Gina and Epperly got to the cabin before the others. When the friends arrived, they saw him but not her. After the friends went down to the beach, they heard Gina’s car leave. Nobody thought anything was awry until they learned that Gina had disappeared. Police found her ankle bracelet and some bloodstains in the cabin (it was before the days of DNA testing). Gina’s car was found abandoned along a riverbank beside a railway trestle bridge. Her clothes and a towel were found nearby.

For obvious reasons, Epperly quickly became the prime suspect in a homicide investigation. Suspicions intensified when police learned that, on the morning after Gina disappeared, Epperly asked a friend who had a lawyer for a brother to find out “if there was anything that they could do to him if they didn’t find a body.” And indeed, the police could find no body.

The investigation quickly became a stalemate. Police suspected Epperly of killing Gina and disposing her body. Epperly claimed Gina had dropped him off at his house; that they had departed on friendly terms and any harm that might have come to her came after they went their separate ways. It was a story that could neither be proven or disproven. After about two weeks, the police brought in a famous tracking dog and its handler. They took the dog to Gina’s car and let it sniff some of Epperly’s clothing. The dog immediately crossed the trestle bridge and led police directly to Epperly’s home. Police then took the dog to the police station parking lot. Epperly was inside being interviewed. The dog identified Epperly’s car and then followed a scent into the police station and to the room where Epperly was being interviewed. The handcuffs went on and Epperly went to prison.

Here is what is interesting.

At trial, Epperly’s lawyers argued that the dog could not have followed the scent from Gina’s car to Epperly’s house. Too much time had passed. The dog handler took the stand and convinced the jury that his dog could perform this feat. However, the dog handler was later described in another trial by another judge as “a liar, a charlatan and a fraud.” Other dog handlers came forward to confirm that no tracking dog could follow a two-week old scent. Further investigation revealed that the police officer who obtained some of Epperly’s clothing from his house had walked from the house to the car. The dog was following the cop’s trail, not Epperly’s.

Epperly filed a federal habeas corpus petition to overturn his conviction on the grounds that the dog’s evidence was flawed. He had a point, but the federal court judge told him to stay in jail. The reasoning was simple and compelling. When the dog had entered the interview room and police told him about how it had tracked him from the car to his house, Epperly put his head in his hands and said (four times), “That’s a damn good dog.” At trial, this response had been ruled admissible, and had been treated as a compelling quasi-confession. The federal court judge ruled that the jury would have convicted on the basis of this statement and the circumstantial evidence. The “dog-tracking provided a merely cumulative link between Epperly and Hall’s death.”

So – in response to the question – “How much is that doggie (worth) in the courtroom”, the answer is: often a lot, but it depends on the amount of other evidence as well.

This post is derived from my just-published book No-Body Homicides: The Evolution of Investigation and Prosecution published by Routledge. It’s got lot’s of interesting stories and wrestles with issues such as this doggone one - and is ideal both as a textbook for criminology classes on investigations or as general reading for afficionados of true crime.